function STcode = generateSTcode()
% generateSTcode.m generates GLONASS ST-code (M-sequence).
%
% STcode = generateSTcode()
%
%   Inputs:
%       None.
%
%   Outputs:
%       STcode      - a vector containing the desired ST code sequence 
%                   (chips).
  
%--------------------------------------------------------------------------
%                           SoftGNSS v3.0
% 
% Copyright (C) Darius Plausinaitis
% Written for scilab 5.3.0 by Artyom Gavrilov
%--------------------------------------------------------------------------
%This program is free software; you can redistribute it and/or
%modify it under the terms of the GNU General Public License
%as published by the Free Software Foundation; either version 2
%of the License, or (at your option) any later version.
%
%This program is distributed in the hope that it will be useful,
%but WITHOUT ANY WARRANTY; without even the implied warranty of
%MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%GNU General Public License for more details.
%
%You should have received a copy of the GNU General Public License
%along with this program; if not, write to the Free Software
%Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
%USA.
%--------------------------------------------------------------------------
  
  reg = -1*ones(1,9);
  for i=1:511
    g3(i)=reg(7);
    msave=reg(5)*reg(9);
    reg(2:9)=reg(1:8);
    reg(1)=msave;
  end;
  STcode=-g3; 
